Pityriarubins, Biologically Active Bis(indolyl)spirans from Cultures of the Lipophilic Yeast Malassezia furfur

Abstract

Indole alkaloids, such as pityriarubin A (1), may be of importance for the pathogenesis of the common skin disease pityriasis versicolor. The metabolite 1 is produced in cultures of the lipophilic yeast Malassezia furfur with tryptophan present as the sole source of nitrogen. The structures of the pityriarubins were derived from spectroscopic investigations, and insight into their biosynthesis was gained by feeding experiments with [1′‐13C]tryptophan.

Generation of Indole Alkaloids in the Human‐Pathogenic Fungus Exophiala dermatitidis

“…[10] For instance, it has been shown that pityriacitrin (3) is an efficient protector against UV light. [7] The pityriarubins [18] isolated from Malassezia furfur inhibit the oxidative burst of human granulocytes, [19] thus explaining why the skin is not inflamed on the parts which are infected by this fungus.…”

Simple indole alkaloids and those with a nonrearranged monoterpenoid unit

“…183 The three biologically active bis(indolyl)spirans, pityriarubins A-C (354, 355a, and 355b), have been isolated from cultures of Malassezia furfur. 184 A new metabolite, terrequinone A (356) was isolated from Aspergillus terreus, which occurs in the rhizosphere of Ambrosia ambrosoides. The structure of 356 was elucidated by spectroscopic methods and chemical derivatization.…”

Characterization of tryptophan aminotransferase 1 of Malassezia furfur, the key enzyme in the production of indolic compounds by M. furfur

“…However, PV characteristics such as pigmentation alterations, fluorescence of PV lesions or minimal signs of inflammation despite high fungal load cannot be explained just by occurrence of M. globosa . Instead, it was shown that with tryptophan as a nitrogen source, Malassezia furfur produces a number of indole pigments and alkaloids, which are related to the clinical appearance of PV . In a previous study, we determined for the model organism Ustilago maydis that tryptophan and keto acids are converted to indole‐3‐pyruvic acid (IPyA) and the corresponding amino acids – a reaction involving a tryptophan aminotransferase (Tam1) in the initial enzymatic step.…”